Colonic Diverticulosis on CT

Colonic diverticulosis on CT is a very common finding that increases with age.  Colonic diverticulosis means that there is an outpouching extending beyond the colon wall.  They are usually multiple and often filled with air or stool.  They are usually small in size and do not cause symptoms.  They are more common in the sigmoid colon or end of the colon but can occur throughout.  It is thought that they occur as a result of increased pressure in the colon from chronic constipation and straining.

Colonic diverticulosis is so common that it is more unusual not to see it in older patients then to see it.  They are rarely associated with symptoms.  Some radiologists mention colonic diverticulosis in the conclusion or impression section but there is usually no consequence or treatment needed.

Colonic diverticula can become complicated by bleeding and inflammation.   Colonic diverticula are the most common cause of bleeding in older adults and results in brisk bleeding from the rectum.  An inflamed diverticulum is called diverticulitis.  This can be a life threatening condition where the diverticulum or outpouching becomes blocked and inflamed   There will often be pain, typically in the left lower abdomen, fever and abnormal labs.

Colonic diverticulosis is therefore significant because of the potential consequences which can happen.  These do not occur in all patients but a minority.   Bleeding of a diverticulum is often a clinical diagnosis as colon bleeding is often not detected on CT.  Inflammation or diverticulitis is diagnosed by CT.  Complications such as perforation of the colon and abscess are also seen on CT.

it is therefore important to know that you have diverticula as this can provide reasons for future rectal bleeding or lower abdominal pain.  A CT scan will help diagnose diverticulitis and it’s complications.  It can also provide any alternate diagnosis even in the presence of diverticula.